If Sonar doesn't work, then I'd advise you to go download
N-Track. It's free (you have to upgrade for the 24bit version) and it's easy to learn. That will allow you to use as many tracks as you want.
As for phase problems, those will only matter with anything that ISN'T close miced, so you don't need to worry with anything except the drum overheads (I think, at least).
For your application, you might want to start out JUST recording drums, then overdubbing the other instruments. The lowest track count you can have for (IMHO) a decent drum set is four, two ohs and a snare and a kick. Then after that you can just od everything one at a time. If you want to do everything together, you're going to be picking up everything in the drum overheads, so that could cause a problem.
If you want to go 10 track, mic them, and record them all at the same time, I'd advise getting a mixer with direct outs, or inserts in every channel, that way to can send them all to a soundcard that has multiple ins. If you're going to go the (cheaper) way and only get four like I said, you can get something like a
delta 44 or
66 and use the 4 ins on it. If you go ten, then you'll need something like a
delta 1010. Yeah they're expensive, but it's what you need.
For mixers, I'd say go for either a Soundcraft
E Series (which have inserts on every channel) or a Soundcraft
M Series.